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This article proposes a design method for a high-speed response motor system consisting of a motor and load. Various methods have been studied to improve the speed response of the motor system, but the main focus was previously advanced control techniques. However, the dynamic response of the controller can be further improved with the high-speed response motor system. The proposed method improves the speed response by increasing the bandwidth of the motor system, which is the plant of the servo system. Thus, the relationship between the bandwidth, which is an indicator of speed response and the motor system, is investigated. The motor system consists of the electrical and mechanical parameters. As both electrical and mechanical parameters affect the speed response and bandwidth of the motor system, the correlation of the time constants and bandwidth is analyzed. Based on the analyzed results, the process of designing a motor system with maximized bandwidth is introduced. An experimental based friction model is proposed to estimate the accurate speed responses and required torque of the motor system. Therefore, a motor system with maximized bandwidth is designed using the proposed design process and friction model. Finally, the rated power and speed response of the motor system are verified through simulations and experiments.

This paper proposes a design method for a high speed response motor system consisting of a motor and load. Various methods have been studied to improve the speed response of the motor system, but the main focus was previously advanced control techniques. However, the dynamic response of the controller can be further improved when the dynamic response of the plant improves. The proposed method improves the speed response by increasing the bandwidth of the motor system which is the plant of the servo system. Thus, the relationship between the bandwidth and speed response has been investigated. As the both electrical and mechanical parameters affect the speed response and bandwidth of the motor system, the correlation of the time constants and bandwidth were analyzed. Based on the analyzed results, the process of designing a motor system with maximized bandwidth was introduced. Therefore, a motor system with maximized bandwidth was designed using the proposed design process. Finally, the rated power and speed response of the motor system were verified through simulations.

This paper introduces a slotless synchronous motor that uses toroidal winding. Unlike the usual winding technique, in which the coil is wound around the stator teeth, a toroidal winding is wound along a ring-type stator yoke. First, this paper describes the structure of a slotless motor that uses toroidal winding. The structural advantages and disadvantages of the motor are also discussed. Next, the finite element analysis method is used to examine the motor’s back electromotive force waveforms according to the rotating magnetic field and permanent magnet position to determine whether the motor is driven with respect to the toroidal coil structure. Finally, to validate the proposed motor, a prototype was built, and its back electromotive force and cogging torque were measured. In addition, dynamo load testing was used to examine the torque generation and performance of the motor.

This paper proposes a design guideline for selecting the pole and slot combination of an outer-rotor permanent magnet synchronous motor (PMSM) using a maximum slot occupation (MSO) coil. Because the MSO coil has a large conductor area, the AC Joule loss in the conductors may be increased at high frequencies. To ensure high-efficiency for the PMSM, it is necessary to reduce the loss. Thus, it is important to select the pole- and slot- combination that has the minimum AC Joule loss. The loss is caused by skin/proximity effects and variations in the slot leakage flux. The skin effect is due to the armature winding and the variation in the slot leakage flux is due to the field flux. A method for separating the AC Joule loss due to each component using the frozen permeability method is proposed. Based on the proposed method, the effect of each cause on the loss at various pole- and slot- combinations is analyzed in this study.

This paper presents a performance estimation method of the induction motor (1M) using the artificial neural network (ANN). The ANN is utilized to approximate the performance such as the current, power factor, torque, and efficiency. Due to the learning characteristics of the ANN, the overall performance of IM can be predicted only by the data of a specific section. The proposed method can save a lot of time, effort, and cost since measuring all the driving sections is not necessary. Finally, in order to verify the estimates, the experiments were conducted under equivalent conditions and the estimates were compared with measured values.

This paper reports the variation in the parameters of PMSM(Permanent Magnet Synchronous Motor) according to the fill factor (i.e., ratio of slot area to conductor area) for a traction motor of EV(Electric Vehicle) and HEV(Hybrid Electric Vehicles). Specifically, we compared fill factors (Concuctor area / Slot area) of 54% from a typical rectangular coil and S6.7% from a MSO (maximum slot occupation, patented design) coil considering a 16-pole 24-slot surface permanent-magnet motor. In addition, we evaluated the current density distribution and thermal characteristics of the conductor (i.e., copper) by 2-D time harmonic and 2-D transient thermal analyses. Moreover, we characterized the copper loss at the d-q axis equivalent circuit of motor and determined the motor characteristics under load operation. The results show that the MSO coil performs higher effeciency of motor at low speed, also lower thermal generation under the same operational conditions.

A method of vertical and horizontal force estimation for soft physical human–robot interaction by using an air-filled material and a camera was proposed in this study. First, we considered hypotheses for vertical and horizontal force applied to the air-filled material. Second, the prototype of air-filled material and vision-based force-sensing device (AVFSD) was constructed. Based on the result of preliminary experiments, the relationships between force, pneumatic pressure, and contact surface displacement were formulated. The vertical and horizontal force could be estimated using the AVFSD with percentage errors of 3.6 and 5.8%, respectively, and the hypotheses were verified through the experiments.

This paper presents a study on brushless permanent magnet (PM) slotless motor with toroidal winding (TWSL). Herein, slotted motor with conventional winding (i.e., CWS motor), which has already been applied to the industry, is compared to the TWSL motor. A finite-element analysis is used to comprehend the operation basis of the TWSL motor, including the linkage flux, back electromotive force, and torque. The proposed TWSL motor can generate the torque level as much as the CWS motor does. The proposed TWSL motor is manufactured and experimented upon to validate the finite-element analysis result.

This paper presents a reluctance-type limited-angle torque motor (LATM), which is used for actuator or arming device in the aerospace industry, and its electromagnetic (EM) characteristics were examined with respect to changes in the rotor pole angle and the rotational position of the LATM. Among the various shape design parameters of the LATM, changes in the rotor pole angle theoretically influence the cross-sectional area of the air-gap, thereby influencing torque generation. A three-dimensional EM finite-element analysis (FEA) was used to evaluate the irregular distribution of the magnetic flux inside the LATM. Finally, an LATM model having a pole angle at which the average and maximum torque become the largest and the torque ripple becomes the smallest (20% or lower) was designed.

Drowsy driving can lead to accidents. Therefore, finding methods by which drowsy driving can be prevented is essential. This paper proposes a method of detecting drowsy driving that utilizes the Low Frequency (LF), High Frequency (HF), and LF/HF values of photoplethysmography (PPG) signals measured on fingers and earlobes. In experiments conducted, of 20 subjects, drowsiness was identified in 14 through PPG signals from their fingers. Further, of those 14 drowsy drivers, PPG signals from the earlobes of eight were also used to determine whether they were drowsy while driving.

This paper quantitatively analyzes inductance estimation errors due to temperature variation and proposes accurate experimental estimation methods considering the temperature distribution of an interior permanent magnet synchronous machine (IPMSM). Accurate knowledge of direct and quadrature-axis inductances is essential for high-performance control of an IPMSM. From the quantitative error analysis results, it is shown that the temperature variation is a very sensitive factor for the accuracy of the experimental estimation of the inductances. For accurate temperature consideration, two experimental estimation approaches are proposed. One uses the temperature measured at end windings to represent the internal temperature of the machine. The other uses both the measured temperature and other temperature information obtained from a temperature distribution analysis. This paper carries out a case study in which the proposed estimation methods are applied to a sample IPMSM with ferrite magnets. Experimental results are compared with finite element analysis (FEA) results in order to verify the effectiveness of the proposed methods.

This paper presents modeling of core loss resistance for d-q equivalent circuit analysis of IPMSM considering harmonic linkage flux. High efficiency is one of the major advantages of IPMSM, therefore precise loss analysis is required for high efficiency design. However, there is practical limitation of d-q equivalent circuit analysis in the calculation of core loss due to harmonic components of flux especially in high speed region where field weakening is generally applied. Harmonic components of linkage flux leads to the underestimation of core loss. Especially operation with high constant speed power range results in severe underestimate of core loss. Harmonic components of linkage flux are added to the general d-q axis equivalent circuits in this paper, therefore core losses due to harmonic components are considered by increased voltage drop across core loss resistance. From the presented modeling of core loss resistance, precise core loss can be obtained. Verification with FEA and experiments are presented.

This paper presents size reduction of primary iron core for tubular linear induction motor by improved winding configuration. Using one-ampere conductor method, magnetic field analysis of tubular linear induction motor for size reduction is conducted. Size reduction and improvement of air gap flux distribution is achieved by improved winding configuration, and analysis results are verified by finite element analysis (FEA) and experiments.

This paper presents various flux-barrier designs in an interior permanent magnet synchronous motor (IPMSM) for reducing torque pulsation. A conventional single-layer IPMSM model, a popular double-layer IPMSM model and two novel double-barrier IPMSM models featuring as a double pairs of flux-barrier flexibly coupled with the simplest single-layer PM, are built and compared together. The geometries of flux-barrier structure in each IPMSM model are optimized by performing response surface methodology (RSM) for minimizing torque ripple and cogging torque. The presented IPMSM models are analyzed by using finite element analysis (FEA), and the validity is confirmed by experiment. Finally, the beneficial attributes of the proposed novel double-barrier IPM designs compared with the single-layer and double-layer IPM designs are emphasized.

Magnetic field analysis of claw-pole machines using improved equivalent magnetic circuit (EMC) is presented in this paper. On the basis of 3-D geometry, improved EMC, which consists of magneto motive-force (MMF) source and permeance considering main and leakage flux distribution, is composed and field analysis is performed. Nonlinear characteristics of magnetic core are considered for precise analysis results. Three-dimensional finite element analysis (FEA) is performed to verify calculated results and flux density in rotor and stator areas are compared. In addition, calculated and experimental back-EMF versus MMF of field and rotor speed is compared. From the verification with calculated and experimental results, it is proved that improved EMC compared with 3-D FEA provided reasonable results in initial design of claw-pole machine having asymmetric structure.

This paper deals with the loss distribution of a three-phase induction motor (IM) and a BLDC motor considering operating point-of-core material based on the FEA and experiments. In order to increase motor efficiency, a high grade of core material can be used. However, sometimes it decreases or provides no improvement of efficiency. This is due to the fact that high-grade core materials generally have lower saturation flux density and core loss. Therefore, when operation of point-of-core materials is in a high-saturation region with low frequency, there could be no significant improvements or decrease of efficiency. The presented results give guidelines to selecting core materials to improve motor efficiency.

This paper introduces the parameter prediction and modelling methods for the traction motor of hybrid electric vehicle (HEV). In the general HEV simulation, the traction motor is mainly defined by efficiency map and torque/speed curve. Therefore, this paper will focus on the prediction of these parameters, which involves the numerical analysis on the motor inductances calculation, iron-loss resistance calculation, and characteristic estimation algorithm and so on. The modelling method is split into tow major parts: configuration of model and composing graphic user interface (GUI). An experiment result will be used to compare with the calculated efficiency map to verify the validity of these methods. In addition, the model construction will be explained by flowcharts. Considering popularity, the MATLAB/Simulink will be used to construct the simulation program. And a GUI will be designed and used to show the simulation results. With the other models of vehicle components, the simulation will be processed in a parallel-type HEV model in an urban road condition (FTP72), and the simulation results will be shown in the end of this paper.

Generally, design of the parts of an automobile is restricted by space especially components assembled in the engine room. Therefore traction motor for hybrid electric vehicle is designed by interior permanent magnet synchronous motor (IPMSM). The IPMSM has high power density and efficiency because it generates not only magnetic torque but also reluctance torque. However, IPMSM is difficult to design due to magnetic saturation and lots of analysis methods are required. Equivalent circuit analysis (ECA) is one of the design methods of IPMSM and it is generally used for characteristics analysis. Using the ECA, we can calculate the characteristics quickly. However, ECA can not estimate line current exactly because of saturation of magnetic core and flux weakening control. In order to perform the ECA exactly, calculation of parameters such as phase resistance, d- and q-axis inductance and no-load linkage flux are important. The phase resistance is simply calculated by using linear equation which is geometrical problem. However, dand q-axis inductance is nonlinear problem which is varied with current level and current angle. Therefore, nonlinear finite element analysis is necessary. Conventional ECA is considered only d- and q-axis inductance profile but no-load linkage flux is considered as constant value. However, no-load linkage flux of IPMSM is also varied according to current level and current angle similar with d- and q-axis inductance profile. Therefore, no-load linkage flux profile which is calculated case of current level and current angle should be considered in the ECA. In this paper, the calculation method of no-load linkage flux profile is introduced firstly and then characteristic of specific model is analyzed with proposed method. The result of line current from improved ECA is compared with experimental result and result of conventional ECA.

The analytical method of images using magnetic charge is applied to analyze characteristics of the slotless axial-flux type brushless dc motors in this paper. The theory of analytical method is introduced and flux density distribution is calculated and verified by three-dimensional finite element analysis. Then, characteristics between single and dual gap axial-flux motor are analyzed and compared

This paper presents rib design in the rotor of IPMSM to increase maximum power in the field weakening region without variation of PM usage, conductor and size. Rib design is critical issue in the design of IPMSM due to leakage flux of permanent magnet and dominated by mechanical strength, therefore structural analysis should be conducted and minimum thickness should be selected. Rib design also affects to the inductance and saliency ratio and results in the variation of the field weakening performance and output power. With determined rib thickness, motor parameters and other motor characteristics according to rib length are presented in this paper. By redesigning rotor ribs, 10% of increased maximum power in the field weakening region is achieved. Finite element analysis (FEM) and equivalent circuit analysis are used for parameter and performance estimation, and designed motor is verified by experiments.

This paper presents size reduction of primary iron core for tubular linear induction motor by improved winding configuration. Using one-ampere conductor method, magnetic field analysis of tubular linear induction motor for size reduction is conducted. Size reduction and improvement of air gap flux distribution is achieved by improved winding configuration, and analysis results are verified by finite element method and experiments.

Optimization of geometry is the one of the most important process in the electrical motor design. Among of the various design parameters tooth and yoke width are the dominate variables that can maximize he back electromotive force (Back-EMF) and on-load torque. In this paper, in order to design the tooth and yoke width effectively, an equivalent magnetic circuit used to calculate the reluctance is proposed. The optimal value of tooth and yoke width for minimizing total reluctance can be obtained by this equivalent magnetic circuit rather than by time-consuming finite element analysis (FEA). The proposed method will be compared with FEM to verify its validity.

The influence of various design parameters on the back electromotive force (back-EMF) and its total harmonic distortion (THD) in surface type permanent magnet synchronous machine (SPMSM) is investigated in this paper. The ratio of pole angle, slot opening, pole number and size of SPMSM are chosen as the design parameters. By using analytical method based on the space harmonic analysis, the variation of back-EMF and back-EMF THD are estimated and mapped according to the variety of these design parameters. And parameter results will be selected by range for meeting the characteristic requirements of SPMSM. The study results of this paper will be helpful to the PMSM design with back-EMF and THD optimization. The results will be verified by the finite element analysis.

This paper presents modeling of motor parameter for parametric design of interior permanent magnet synchronous motor(IPMSM). Parametric design gives effective motor parameters for IPMSM considering control strategy. Characteristics of IPMSM are greatly influenced by Ψ a , L d and L q . Parametric design provides motor characteristics according to variation of and Ψ a , L d by solving voltage equations of d-q axis equivalent circuit. Modeling of other parameters according to variation of Ψ a and L d are presented and appropriate design process is introduced.

An improved AC standstill inductance measurement method for interior permanent magnet synchronous machine (IPMSM) is proposed in this paper. Only the 3-phase voltage source, oscilloscope, and DC voltage source are required, rather than the dynamometer and inverter in the other methods. Depending on the deduced q- and d-axis voltage equations in the stationary reference frame, the q- and d-axis inductances at different current magnetite and vector angle can be calculated by the measured 3-phase voltages and currents. Thus, the saturation and cross-magnetizing effect of the inductances are measurable. This paper will introduce the principle equations, experiment setup, data processing, and results comparison.

This paper deals with a design approach to an interior permanent magnet synchronous motor (IPMSM) used in in-wheel motor drive systems of electric vehicles. The approach is divided into three parts overall. First, the constant power region of IPMSM and gear ratio are investigated in order to meet the specifications of the in-wheel motor system. Second, the range of inductance and back-EMF to satisfy the given design conditions of the IPMSM is estimated. Finally, the preliminary geometry satisfying the range is decided by PM type, current density, and fill factor and so on, and then the detailed design is carried out by means of finite element analysis in consideration of magnetic saturation.

An improved AC standstill inductance measurement method for interior permanent magnet synchronous machine (IPMSM) is proposed in this paper. Only the 3-phase voltage source, oscilloscope, and DC voltage source are required in this method, rather than the dynamometer and vector controller in the other methods. Depending on the derivative q- and d-axis voltage equations in the stationary reference frame, the q- and d-axis inductances at different current magnetite and vector angle can be calculated by the measured 3-phase voltages and currents. And hence, the saturation and cross-magnetizing effect of the inductances are measurable. This paper will introduce the principle equations, experiment setup, data processing, and results comparison.

This paper studies the influence of permanent magnet on the total system efficiency of permanent magnet synchronous motors (PMSM). Two PMSM with Nd-Fe-B and Ferrite magnets which have same Back-EMF and output power have been designed. First, the dynamic simulation is performed with these two motors' parameters. The current waveforms and switching losses of transistors can be evaluated. And then, by means of the obtained current waveforms and a series of numerical methods, the iron losses of these two motors will be calculated. Finally, comparing the sum of the switching losses and iron losses, the result can be used to reflect the influence of the magnet on the total motor system efficiency.

Interior Permanent Magnet Synchronous Motor (IPMSM) which has high power and high efficiency is usually applied to traction motor for hybrid electric vehicle. We focused on the following points: Flat wire coil, Interior permanent magnet.

This paper presents core loss analysis of 3-phase induction motors used for industry applications. The core loss is affected by the time rate of the change of magnetic flux density. Generally core loss is spread out in stator and rotor core. And, rotor core toss is less than stator core because of constant field flux density of rotor. Tooth core loss density is large than yoke core loss because tooth has harmonic distortion of flux density. In this paper, transient finite element method used to analyze the magnetic flux density waveform in order to analysis the flux density according to varying time. Core losses in each element are evaluated using core loss curve tested by and Epstein test apparatus. Its result is shown the distribution of core loss density and partial thermal source.

An inductance measurement method for interior permanent magnet synchronous machine (IPMSM) is proposed in this paper. In this method, the motor is measured at standstill condition, and only a 3-phase voltage source, an oscilloscope and a DC voltage source are required. Depending on the deductive dq-axis voltage equations in the stationary frame of reference, the dq-axis inductances at different current magnetite and vector angle can be calculated by the measured 3-phase voltages and currents. And hence, the saturation and cross-magnetizing effect of the inductances are measurable. This paper introduces the principle equations, experiment setup, data processing, and results comparison on the concentrated-winding and distributed-winding IPMSMs.

This paper presents motor characteristics and radial magnetic force (RMF) of interior permanent magnet synchronous motors (IPMSM) according to pole/slot combinations. Three IPMSM of 15, 18, 24 slots with 16 poles are selected; 16 poles 15 slots and 18 slots provide high winding factor and 16 poles 24 slots is a general pole-slot combination. Using finite element analysis (FEA) and equivalent circuit analysis, output characteristics and motor parameters such as back electro-motive force (bemf), inductance, etc. are compared, and RMF in air gap causing noise and vibration is investigated. It is expected that presented study results help with appropriate choice of pole and slot number of IPMSM.

Performance comparison of IPMSMs with distributed and concentrated windings is presented in this paper. Two IPMSMs have been designed with identical rotor dimensions, air gap length, series turn number, stator outer radius, and axial length except winding configuration. Basic parameters and output characteristics, such as inductances, resistances, back emf, output torque, and efficiency, are compared. Design strategy about winding configuration is discussed.

In this paper, an analytical method based on conformal mapping technique is applied to the rotor design of interior permanent magnet synchronous motor (IPMSM). A single layer IPMSM is developed to a double-layer IPMSM to improve saliency ratio with design of experiment (DOE) and response surface methodology (RSM). The increased reluctance torque of the double-layer IPMSM is verified by finite element analysis (FEA). With this analytical method, the estimation of saliency effect related to reluctance torque can be achieved by simple calculation of equations. Therefore, time and effort in the initial design of the model having complex geometry can be saved

In this paper, distributed and concentrated winding type interior permanent magnet synchronous machines are designed and compared to use for an integrated starter generator. The characteristics are computed from equivalent circuit which consists of parameters obtained from finite element analysis. The comparison results are discussed, and the determined model is fabricated and tested

The design of 2-dimensional equivalent model for claw-pole type generator is presented in this paper. On the basis of 3D geometry, 2D equivalent model is designed and 2D FEA is performed. Comparing to other analysis method for claw-pole type machine, such as 3D FEA and MEC, presented method can be more practically used and directly applied to industry. Flux distribution in the air-gap and flux density at rotor and stator are verified by 3D FEA, and no-load back EMFs for field input voltages are verified by measurement

An analytical method used to predict the magnetic field in an interior permanent magnet (IPM) motor, is developed and validated in this paper. By using space harmonic analysis and conformal transformation (or conformal mapping (CM)) techniques, the air-gap magnetic field distribution, with considering of stator slots effect and rotor saliency effect, is precisely calculated. The accuracy of this analytical method is confirmed by the 2-dimensional finite element analysis (FEA). The analytical method can produces results much faster than FEA alone